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can you fill your own tanks?

Discussion in 'Basic Scuba Discussions' started by goldhunter_2, Aug 12, 2003.

  1. goldhunter_2

    goldhunter_2 Angel Fish

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    I am kinda new to this sport and just found this site (get info) :D I current have a Al80 and think I like the alum My buddy dove with steel before and is dead set that he wants steel tanks. My question is can someone fill there own tanks at home with a reg comperrsor (runs three nail guns, pankcake type) if you add a filter system??:confused:

    If so where can you buy filter systems:confused:
     
  2. Bob3

    Bob3 Dive Shop

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    Scuba tanks take upwards of 2000 psi, and some go as high as 4500 psi. Your little garage compressor only puts out a couple hundred psi at best.
    Most garage style compressors use plain oil to lube the critters, something that'll trash out your lungs very badly if you inhale any.
     
  3. BigJetDriver

    BigJetDriver Great White Rest in Peace

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    The problem with the industrial compressors is the oil content in the air. They put out a lot more of it, compared to a breathing air compressor. Of course, nail guns are not bothered by this in the slightest, but it doesn' t take much for that oil to wreak havoc in your lungs.

    The filters can be purchased and plumbed into such a system, but given the pressures involved, you will be surprised at the cost of the components. Your breathing air compressor will typically run at slightly over 3000 psi output at reasonable cfm rates. Also, your filters will have to be changed a lot, due to the oil, and they are NOT cheap.

    All in all, both for cost and health reasons, you will be better off buying a few extra tanks and having them filled at the shop while you save up for a used SCUBA compressor. :wink:
     
  4. Uncle Pug

    Uncle Pug Swims with Orca ScubaBoard Supporter

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    ... and at 150 psi (if your little pancake can pump that high) your aluminum 80 would contain 4 cf of air.... but not much of that would be usuable since your intermediate pressure (between first and second stage) would drop below its set point after a few breaths.
     
  5. James connell

    James connell Barracuda

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    you can fill your own bottles if you wish - but not with a "std" garage compressor. you need several thousand psi (at a minimum), no garage compressor is going to do that.
    personal scuba compressors are available starting at ~ $2000, they have the filters ( and yes you can purchase aftermarket filters too) included.
    they problem is compressor maintanance/filter replacement, the filters are only good for so many fills and must be replaced. dive shops also have their air tested regularly ( or at least the good ones do).
    the cheaper compressors need to be rebuilt more often also.
    if you do the math you find that an air fill costs about the same as a shop fill after you figure in compressor costs and filter replacement. it is a little more feesable if you do your own gas mixing though. shop trimix fills are considerably more expensive than you can do at home.
     
  6. Genesis

    Genesis Great White

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    First, MOST "small" home-style compressors are oilless, so that won't be the problem. (Larger ones are oil-lubricated)

    However, those compressors only put out 100-150 psi typically, which is nowhere near enough. You need 3000 psi to charge an AL80, and more for HP steels (3500 or so)

    A small "home usable" dive compressor will run you $2500 or so, runs on 240V (requires a 240V outlet or direct wiring) and, as was noted, also requires filters which must be changed on a regular basis - while they're not stupid expensive, they're not cheap either. If you decide you want one, I personally believe that the Alkin W31 is the "best value" in the small compressor market, all things considered. (If you're looking for something larger, in the ~5cfm range, then you need to seriously consider the Coltri-based Max-Air 55 series and the Bauer Oceanus or Capitano, both of which are very nice and a bit cheaper than what Alkin has in THAT size range.)

    Neglect maintenance on said "home compressor" and you will get a lung-full of oil or (at least as bad) CO, which can KILL you.

    IF you dive Nitrox AND live where fills are expensive (more than $6-7 a bottle for Nitrox) then it can be worth it, IF you dive a lot, to put in your own fillstation. I dive perhaps 200 bottles of gas a year between myself and a buddy, so for me, at least, its pretty simple on the math - I have a $2,000 annual gas bill if I buy my gas. In two years or so I pay for the hardware and maintenance - so for me, its worth it.

    But for those who dive infrequently, or dive only air, its almost certainly NOT worth it.

    If you are not anal about doing the required maintenance, its downright dangerous to do your own.
     
  7. Walter

    Walter Instructor, Scuba

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    Everything is true except "not much of that would be usuable since your intermediate pressure (between first and second stage) would drop below its set point after a few breaths."

    While the pressure would drop below the intermediate pressure fairly soon, the regulator would still deliver air from the tank until it reached ambient pressure. Of course, all that air would have the oil previously mentioned.
     
  8. Genesis

    Genesis Great White

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    will get VERY hard to breathe when the tank pressure goes below the IP. If you doubt this I'll put a R190 or R380 on a balanced first where I can tune the IP and set it for 110 psi and let you have a breath or three off it - its like breathing through a straw! At 135 it breathes "normally."

    A balanced second won't show much difference until the pressure gets close to ambient, however.

    Much depends on what kind of reg you have...
     
  9. Bob3

    Bob3 Dive Shop

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    Not by me, the little buggers are oil bath.
    I keep checking 'cuz I'm in need of another little compressor to run an old air hat for the swimming pool.:wink:
    I've used a Sears oilless (teflon rings) to run hardhat off of for a dam job I was doing. It was nice not to have that darn gas engine on our regular dive compressor running & drowning out the comms.
     
  10. Genesis

    Genesis Great White

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    There are a couple of "contractor-type" nail-gun sized compressors with reasonable reservoir tanks that are both portable and oilless.

    The larger, fixed ones are all oil-bath, but the smaller ones tend to be of oilless design, simply due to the transport considerations (tip an oil-filled one over and you get a nice mess!)

    For a hat supply you'd still need a particulate filter..... :)
     

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